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1.
Sci Total Environ ; : 153259, 2022 Jan 19.
Artigo em Inglês | MEDLINE | ID: mdl-35065113

RESUMO

In this study, the nano-scale spatial distribution of natural organic matter (NOM) on the surface of iron (hydr)oxides and its relevance to oxyanion (PO43-) and metal cation (Cd2+ and Cu2+) adsorption to the assemblage of oxide (goethite) and NOM (humic acids (HA) or fulvic acids (FA)) was investigated with experiments and advanced surface complexation modeling. Both the linear additive Multi-Surface model (MSM) and the more sophisticated Natural Organic Matter-Charge Distribution (NOM-CD) model were used. The MSM model ignores the effects of NOM-mineral interaction on ion adsorption, whereas the NOM-CD model considers this effect. The results showed that with the increase of NOM loading on oxides, deviation between the MSM and NOM-CD model became bigger for PO43-, but smaller for Cd2+ and Cu2+. Oxyanions bind mainly to oxides and therefore the competitive effect of NOM cannot be neglected, which explains the large difference between these two models for PO43-. On the contrary, at a relatively high NOM loading, a large fraction of NOM extends further away from the surface of oxides. Thus for metal cations that bind mainly to NOM, the influence of NOM-mineral interaction on their adsorption is small and the results of the MSM and NOM-CD model are similar. In top soils, the NOM loading on oxides is often high, therefore the linear additive MSM is applicable for metal cation speciation calculations as reported in many literatures. An approach based on the NOM-CD model was proposed, which can not only calculate the macroscopic solid-solution distribution of both cations and anions, but can also provide information regarding their microscopic surface speciation.

2.
Chemosphere ; 286(Pt 3): 131965, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34449324

RESUMO

The production and degradation of plastic remains can result in nanoplastics (NPs) formation. However, insufficient information regarding the environmental behaviors of NPs impedes comprehensive assessment of their significant threats. In this study, the transport behavior of unmodified NPs (PSNPs), carboxyl-modified NPs (PSNPs-COOH), and amino-modified NPs (PSNPs-NH2) was investigated using column experiments in the presence and absence of goethite (GT) and diethylhexyl phthalate (DEHP). Quantum chemical computation was performed to reveal the transport mechanisms. The results showed that GT decreased the transport of NPs and the presence of DEHP decreased it further. Van der Waals forces and small electrostatic interactions coexisted between the PSNPs and GT and caused deposition. Ligand exchange caused greater deposition of PSNPs-COOH on GT-coated sand than that of PSNPs. Although hydrogen bonding existed between the DEHP and NPs with functional groups, an increase in the positive charge and chemical heterogeneity of the collector was the main reason for DEHP promoting the deposition of NPs. Because of low absolute negative zeta potential values, PSNPs-NH2 was sensitive to chemical heterogeneity, and thus fully deposited (over 96.9%) in GT and GT-DEHP-coated columns. Generally, the deposition of NPs due to chemical heterogeneity was more significant than that due to the formation of chemical bonds and van der Waals, electrostatic, and hydrogen interactions. Our results highlight that the surface charge and functional groups significantly influence the transport behaviors of NPs and elucidate the fate of NPs in the terrestrial environment.


Assuntos
Dietilexilftalato , Microplásticos , Plásticos , Poliestirenos , Areia
3.
J Hazard Mater ; 416: 126260, 2021 08 15.
Artigo em Inglês | MEDLINE | ID: mdl-34492996

RESUMO

Cadmium is an extremely toxic substance known to cause serious health problems. The uptake of Cd in plants is critically affected by dissolved Cd in soil porewater, controlled by soil physicochemical properties. Rhizo-availability of Cd is assumed, as the Cd fraction is found on the plasma membrane of surface root cells. Based on the theory of Cd transformation in soil-crop systems, we established a novel combined mechanistic model related to soil, soil solutions, and crops. The combined model comprises a multisurface model (MSMs; solid adsorbent and porewater) and the Gouy-Chapman-Stern model (GCS; porewater and root surface). The results suggested that in mildly contaminated soil samples, optimum prediction was achieved when DTPA-extractable Cd was used as input variable (R2 = 0.723). Our approach was superior to single-step model calculation (MSMs: R2 = 0.613; GCS: R2 = 0.629) and prediction based on extractable soil Cd (R2 = 0.281). Introducing DTPA extraction expanded the range of model applications at different soil pHs. Our proposed mechanism model was based on soil physicochemical properties for Cd migration from soil to cabbage. Our model showed promise in predicting Cd bioavailability in soil with a wide pH range and evaluating soil risk near the standard Cd safety level.


Assuntos
Brassica , Poluentes do Solo , Disponibilidade Biológica , Cádmio/análise , Solo , Poluentes do Solo/análise
4.
Chemosphere ; 284: 131290, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34198065

RESUMO

The application of herbicide fomesafen plays a crucial role in ensuring global soybean productivity in modern agriculture, but it results in both adverse effects on soil ecosystems and phytotoxicity to succeeding crops. Soil pollution due to herbicides has raised much concern worldwide. However, there has been little investigations concerning their effects on soil fauna, especially on the gut microbial communities of earthworms. In this study, the soil endogeic earthworm Pheretima guillelmi was incubated for 20 days in natural and fomesafen-polluted soils to investigate the effects of the herbicide on gut bacterial microbiota and the earthworm's physiological indices, including energy resource (protein) and antioxidant enzyme (superoxide dismutase, SOD) of earthworms in the soil ecosystem. A significantly different and smaller microbial community was presented in the earthworm's gut compared with the cast and the surrounding soil, with exposure to fomesafen further reducing the bacterial diversity and altering the gut community composition. This was observed as significant changes in the relative abundance of the phyla Actinobacteria, Firmicutes, and Proteobacteria as well as the genera Bacillus, Microvirga, Blastococcus, Nocardioides, and Gaiella. Moreover, exposure to fomesafen reduced earthworms' energy resources and activated the antioxidant system, with both effects being significantly correlated with the gut microbial diversity. These findings unravel the fact that exposure to the herbicide fomesafen may affect non-target soil fauna via changes in their microbiota and physiological indices, thereby contributing new knowledge regarding the adverse impacts of fomesafen on the terrestrial ecosystem.


Assuntos
Microbioma Gastrointestinal , Microbiota , Oligoquetos , Poluentes do Solo , Animais , Benzamidas , Solo , Microbiologia do Solo , Poluentes do Solo/análise , Poluentes do Solo/toxicidade
5.
Sci Total Environ ; 784: 147115, 2021 Aug 25.
Artigo em Inglês | MEDLINE | ID: mdl-34088021

RESUMO

Plastic pollution has become a global threat in the natural environment, and an urgent remedial measure is needed to reduce the negative effects caused by plastic pollutants. In the current study, the effects of pyrolysis temperature (500 °C, 700 °C, and 900 °C) and aging on the adsorption of polystyrene nanoplastics (PSNPs) onto corncob biochar were systematically assessed with kinetic, isotherm, pH-dependent adsorption experiments, FTIR and XPS spectroscopy, and DLVO calculations. The oxidation was done with 5% of HNO3/H2SO4 to simulate long-term oxidative aging of biochar in the environment. The results showed that the specific surface area, hydrophobicity, and aromaticity of biochar increased with pyrolysis temperature, whereas the specific surface area and amounts of oxygen-containing groups increased after oxidation. The adsorption mechanism of PSNPs onto the biochar was explored based on the correlation between biochar properties and adsorption parameters derived from adsorption isotherms. Overall, the adsorption capacity of biochar for PSNPs increased with increased pyrolysis temperature and after aging. While the increase of specific surface area was considered the major factor leading to the increase of the adsorption, the variation in surface properties also played an important role. Pore filling, hydrophobic interaction, and hydrogen bonding may all be involved in PSNPs adsorption to biochar. However, the hydrophobic interaction might be more important for the fresh biochar, whereas hydrogen bonding involving oxygen-containing groups might make a bigger contribution to PSNPs adsorption to oxidized biochar. The pH experiments revealed that PSNPs adsorption decreased in general with the increase of pH, indicating that electrostatic repulsion played a vital role in the PSNPs adsorption process. The results of this study indicate that biochar can be potentially applied to immobilize plastic particles in terrestrial ecosystems such as in soil or groundwater, and the immobilization could be enhanced via artificial oxidation or aging of biochar in the natural environment.

6.
Chemosphere ; 276: 130012, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34088086

RESUMO

Iron (Fe) minerals, organic matter (OM), and pH can effectively regulate phosphorus (P) transport in the soil. However, their respective contributions in this regard are still unclear. In this study, P transport in soil columns was investigated by monitoring breakthrough curves and transport model fitting, and the contributions of Fe and total organic carbon (TOC) concentrations, as well as pH to P retention, were determined using multiple linear regression (MLR). The results showed that the rate of P transport in Fe-rich laterite soil was significantly lower (retardation factor R = 458.5) than that in the other soil types (R = 108.4-247.6). Additionally, it was observed that OM formed rate-limited adsorption sites, causing the rapid release of labile P, and owing to P release and readsorption. Even though more significant P releases were observed, chernozem soil had an obvious inhibiting effect on P transport owing to its relatively high Fe content, and the high P-Fe increment (48.9-90.4%) indicated the essential role of Fe minerals in P immobilization. Further, P was readily transported in natural or artificially modified fluvo-aquic soils with high calcium concentrations, and it was also observed that the convection-dispersion equation (CDE) and Thomas models were suitable for describing P retardation and adsorption, respectively. Furthermore, the contribution weights of Fe and TOC concentrations as well as pH to P retardation, based on MLR calculations, were approximately 1.0, -0.3, and -0.2, respectively. Our findings can support the control of eutrophication pollution caused by P leaching.


Assuntos
Poluentes do Solo , Solo , Adsorção , Eutrofização , Fósforo , Poluentes do Solo/análise
7.
Chemosphere ; 283: 131102, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34146872

RESUMO

Arsenic (As) and cadmium (Cd) are unnecessary metal(loids) toxic at high concentration to plants and humans, hence lessening their rice grain accumulation is crucial for food security and human healthiness. Charred eggshell (EB), corncob biochar (CB), and eggshell-corncob biochar (ECB) were produced and amended to As and Cd co-polluted paddy soil at 1% and 2% application rates to alleviate the metal(loids) contents in rice grains using pot experiments. All the amendments increased paddy yields at 1%, while EB at 2% significantly reduced the yields compared to untreated control. The resulting yield loss in 2%EB was from the combined effects of its high CaCO3 supplementation, and the increment of rhizosphere soil pH which could insolubilize plant nutrients. The amendments were inefficient in decreasing rice grain As (AsGrain), but all the treatments significantly reduced the rice grain Cd (CdGrain) at both 1% (44.4-77.1%) and 2% (79.8-91.5%) application rates compared to that of control. Regression analysis for contribution weights of control factors revealed that rhizosphere soil Eh and pH were vital influential factors regulating the AsGrain, whereas porewater Cd was main factor controlling CdGrain accumulation. These investigations indicated that the Ca-enriched eggshell-corncob biochar even at high application rate (i.e., 2%ECB) could be a potential tactic for grain accumulation remediation of the cationic pollutant (i.e., Cd) from the paddy soil to rice grain scheme with concurrent increase in rice yields.


Assuntos
Arsênio , Oryza , Poluentes do Solo , Arsênio/análise , Cádmio/análise , Cálcio , Carvão Vegetal , Humanos , Solo , Poluentes do Solo/análise
8.
Sci Total Environ ; 785: 147163, 2021 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-33940407

RESUMO

Arsenic (As) and cadmium (Cd) are nonessential toxic metal(loids) that are carcinogenic to humans. Hence, reducing the bioavailability of these metal(loids) in soils and decreasing their accumulation in rice grains is essential for agroecology, food safety, and human health. Iron (Fe)-enriched corncob biochar (FCB), Fe-enriched charred eggshell (FEB), and Fe-enriched corncob-eggshell biochar (FCEB) were prepared for soil amelioration. The amendment materials were applied at 1% and 2% application rates to observe their alleviation effects on As and Cd loads in rice paddy tissues and yield improvements using pot trials. The FCEB treatment increased paddy yields compared to those of FCB (9-12%) and FEB (3-36%); this could be because it contains more plant essential nutrients than FCB and a lower calcite content than that of FEB. In addition, FCEB significantly reduced brown rice As (AsBR, 29-60%) and Cd (CdBR, 57-81%) contents compared to those of the untreated control (CON). At a 2% application rate, FCEB reduced the average mobility of As (56%) and Cd (62%) in rhizosphere porewater and enhanced root Fe-plaque formation (76%) compared to those of CON. Moreover, the enhanced Fe-plaque sequestered a substantial amount of As (171.4%) and Cd (90.8%) in the 2% FCEB amendment compared to that of CON. Pearson correlation coefficients and regression analysis indicated that two key mechanisms likely control AsBR and CdBR accumulations. First, rhizosphere soil pH and Eh controlled As and Cd availabilities in porewaters and their speciation in the soil. Second, greater Fe-plaque formation in paddy roots grown in the amended soils provided a barrier for plant uptake of the metal(loids). These observations demonstrate that soil amendment with Fe-enriched corncob-eggshell biochar (e.g., 2% FCEB) is a prospective approach for the remediation of metal accumulation from the soil to grain system while simultaneously increasing paddy yield.


Assuntos
Arsênio , Oryza , Poluentes do Solo , Arsênio/análise , Cádmio/análise , Cálcio , Carvão Vegetal , Humanos , Ferro/análise , Solo , Poluentes do Solo/análise
9.
Cell Mol Biol Lett ; 26(1): 19, 2021 May 18.
Artigo em Inglês | MEDLINE | ID: mdl-34006215

RESUMO

BACKGROUND: Some natural compounds inhibit cancer cell growth in various cancer cell lines with fewer side effects than traditional chemotherapy. Here, we explore the pharmacological effects and mechanisms of worenine (isolated from Coptis chinensis) against colorectal cancer. METHODS: The effects of worenine on colorectal cancer cell proliferation, colony formation and cell cycle distribution were measured. Glycolysis was investigated by examining glucose uptake and consumption, lactate production, and the activities and expressions of glycolysis enzymes (PFK-L, HK2 and PKM2). HIF-1α was knocked down and stimulated in vitro to investigate the underlying mechanisms. RESULTS: Worenine somewhat altered the glucose metabolism and glycolysis (Warburg effect) of cancer cells. Its anti-cancer effects and capability to reverse the Warburg effect were similar to those of HIF-1α siRNA and weakened by deferoxamine (an HIF-1α agonist). CONCLUSION: It is suggested that worenine targets HIF-1α to inhibit colorectal cancer cell growth, proliferation, cell cycle progression and the Warburg effect.


Assuntos
Benzodioxóis/farmacologia , Proliferação de Células/efeitos dos fármacos , Glicólise/efeitos dos fármacos , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Quinolizinas/farmacologia , Pontos de Checagem do Ciclo Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Neoplasias do Colo/metabolismo , Neoplasias do Colo/patologia , Humanos , Subunidade alfa do Fator 1 Induzível por Hipóxia/antagonistas & inibidores , Subunidade alfa do Fator 1 Induzível por Hipóxia/genética , Proteólise/efeitos dos fármacos , Interferência de RNA , RNA Interferente Pequeno/metabolismo
10.
Chemosphere ; 280: 130731, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-33971411

RESUMO

Cd and As are difficult to co-remediate in co-contaminated soils. In this study, remediation materials comprising large-grained and nano-sized biochar (BC), ferrihydrite (FH), and complexes thereof were added to Cd- and As-contaminated soil. The uptake of Cd and As by pak choi (Brassica chinensis L.) was then evaluated using a pot experiment and the Cd and As concentrations of the soil pore water and leaching water were measured. The Cd and As concentrations of the pore and leaching water were slightly increased with the addition of BC, and decreased with addition of FH and the biochar-ferrihydrite complex (BC-FH). However, nano-sized BC (BCN), FH (FHN), and BC-FH (BC-FHN) had little influence on the decreases in Cd and As of the two monitored water types. Large-grained remediation materials, rather than nanomaterials, decreased the Cd and As concentrations of the two monitored water types. Nonetheless, nanomaterial treatments more effectively decreased the Cd and As concentrations in plants by an average of >10% relative to the large-grained treatments. The DLVO theory analysis suggested that BCN, FHN, and BC-FHN, immobilized in the topsoil, adsorbed heavy metals in the rhizosphere soil. The remainder of the nano-sized materials was dispersed in the rhizosphere soil pores, shielding the uptake of Cd and As by the roots. Although the doses of nanomaterials used in this study were less than one-fortieth of those of the large-grained materials, changes in the plant rhizosphere microenvironment caused by the nanomaterials decreased the risk of toxicity transfer from the soil to the plants.


Assuntos
Cádmio , Poluentes do Solo , Cádmio/análise , Carvão Vegetal , Compostos Férricos , Solo , Poluentes do Solo/análise
11.
Chemosphere ; 280: 130639, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-33962295

RESUMO

Phthalates (PAEs) often exist simultaneously in contaminated soil and wastewater systems, and their adsorption to biochar might impact their behavior in the environment. So far, the competitive adsorption of PAEs to biochar has not been reported. In this study, the competitive adsorption of Dibutyl phthalate (DBP) and Di(2-ethylhexyl) phthalate (DEHP) on corncob biochar (fresh and oxidized) was investigated, and experiments of kinetics, isotherms, and thermodynamics were conducted. Langmuir and Freundlich models, pseudo-first-order and second-order kinetic models were used to simulate the experimental data. In the mono PAEs component systems, the biochar showed significantly greater adsorption capacity for DEHP (11.8-16.16 mg g-1) than for DBP (9.86-13.2 mg g-1). The oxidized biochar has higher adsorption capacities than the fresh one. Moreover, a fast adsorption rate for DBP was observed, which can be attributed to the smaller size and shorter carbon chains in the DBP molecule, resulting in faster diffusion into the biochar pores. In the binary PAEs component systems, competition between DEHP and DBP in their adsorption to the biochars was observed, and DEHP (11.7-15.0 mg g-1) was preferred over DBP (3.4-7.9 mg g-1). The stronger adsorption of DEHP can be explained by stronger hydrophobic interaction with biochar. Compared to DBP, DEHP has a high octanol-water partition coefficient (logKow) and low water solubility. The positive entropy (ΔS0) and enthalpy(ΔH0) values for the adsorption of both DEHP and DBP further indicated that hydrophobic interaction played an important role, even though H-bonds and π-π interactions could also be involved.


Assuntos
Dietilexilftalato , Ácidos Ftálicos , Adsorção , Carvão Vegetal , Dibutilftalato , Zea mays
12.
Sci Total Environ ; 781: 146679, 2021 Aug 10.
Artigo em Inglês | MEDLINE | ID: mdl-33798888

RESUMO

The impacts of two ecological earthworms on the removal of chlortetracycline (CTC, 0.5 and 15 mg kg-1) and antibiotic resistance genes (ARGs) in soil were explored through the soil column experiments. The findings showed that earthworm could significantly accelerate the degradation of CTC and its metabolites (ECTC) in soil (P < 0.05), with epigeic Eisenia fetida promoting degradation rapidly and endogeic Metaphire guillelmi exhibiting a slightly better elimination effect. Earthworms alleviated the abundances of tetR, tetD, tetPB, tetG, tetA, sul1, TnpA, ttgB and intI1 in soil, with the total relative abundances of ARGs decreasing by 35.0-44.2% in earthworm treatments at the 28th day of cultivation. High throughput sequencing results displayed that the structure of soil bacteria community was modified apparently with earthworm added, and some possible CTC degraders, Aeromonas, Flavobacterium and Luteolibacter, were promoted by two kinds of earthworms. Redundancy analysis demonstrated that the reduction of CTC residues, Actinobacteria, Acidobacteria and Gemmatimonadetes owing to earthworm stimulation was responsible for the removal of ARGs and intI1 in soil. Additionally, intI1 declined obviously in earthworm treatments, which could weaken the risk of horizontal transmission of ARGs. Therefore, earthworm could restore the CTC-contaminated soil via enhancing the removal of CTC, its metabolites and ARGs.


Assuntos
Clortetraciclina , Oligoquetos , Poluentes do Solo , Animais , Antibacterianos/farmacologia , Clortetraciclina/farmacologia , Resistência Microbiana a Medicamentos/genética , Solo , Poluentes do Solo/análise
13.
Artigo em Inglês | MEDLINE | ID: mdl-33652570

RESUMO

Source identification of heavy metals in agricultural soils using small sample sizes, simple experimental procedures, and convenient analysis is urgently required. This study employed a simple source identification model using a visual comparison via radar plots, cluster analysis, principal component analysis, and a multiple linear regression model to determine the source of heavy metal pollution in soil samples from the Chang-Zhu-Tan urban agglomeration area of China. The elemental compositions of major pollution sources (atmospheric deposition, organic fertilizer, irrigation water, and tailings) were compared with soil samples from 11 study locations and the model was used to determine the relative contribution of different pollution sources at each sample site. The results showed that the model successfully calculated the contribution of different pollution sources at each site based on the pollution characteristics and contaminant transport rules of the region. The proposed method overcomes the requirement for extensive data and complex experimental procedures. Furthermore, the model can determine the source of heavy metal contamination in single or small plots, which is important for the prevention and control of heavy metal soil pollution and remediation at the plot scale.


Assuntos
Metais Pesados , Poluentes do Solo , China , Monitoramento Ambiental , Metais Pesados/análise , Solo , Poluentes do Solo/análise
14.
Sci Total Environ ; 778: 146281, 2021 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-33721639

RESUMO

The widespread presence of phthalate esters (PAEs) in a variety of agricultural inputs has led to PAE contamination in soils and farm products. The endocrine disruption and carcinogenicity of PAEs have attracted much attention. Our research investigated the characteristics of PAE pollution in the soils of vegetable fields and adjacent stable crop fields in four provinces/municipalities across a major agricultural production area in China. We found that the concentrations of PAEs in vegetable soils were not significantly higher than those in stable crop soils. The noncarcinogenic and carcinogenic risks from bis (2-ethylhexyl) phthalate (DEHP) and dibutyl phthalate (DBP) to humans were calculated to represent the risk posed by PAEs. The results showed that diet was the main route for noncarcinogenic risks from PAEs in crop soil and vegetable soils. Because of the combined effect of the population dietary structure and the concentration of PAEs in soils, the noncarcinogenic risks from PAEs in crop soils were similar to or higher than those in vegetable soils. The same pattern was also applicable to the carcinogenic risk from DEHP. Low noncarcinogenic and carcinogenic risks posed by DEHP and DBP indicated that the current level of PAEs in soils did not decrease the safety of agricultural products in the Huang-Huai-Hai region. Stable crop soil, as a non-negligibly phthalate-polluted area, is worthy of as much attention as vegetable soil. This study provides scientific support for food safety risk assessment and control of PAE pollution in the main agricultural production areas in China.


Assuntos
Ácidos Ftálicos , Poluentes do Solo , China , Cidades , Dibutilftalato/análise , Dibutilftalato/toxicidade , Ésteres/análise , Humanos , Ácidos Ftálicos/análise , Solo , Poluentes do Solo/análise , Verduras
15.
J Environ Sci (China) ; 100: 144-157, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33279027

RESUMO

Zero-valent iron amended biochar (ZVIB) has been proposed as a promising material in immobilizing heavy metals in paddy fields. In this study, the impacts of pH of ZVIB (pH 6.3 and pH 9.7) and watering management techniques (watering amount in the order of CON (control, 5/72)>3/72>1-3/72>3/100>1/72, with 5/72, for example, representing irrigation given to 5 cm above soil surface in 72 hr regular interval) on As and Cd bioavailability for rice and its grain yield (YieldBR) were investigated in a pot experiment. Brown rice As (AsBR) content was irrelative to the watering treatments, while significantly decreased (>50%) with the addition of both ZVIB materials. The diminutions of brown rice Cd (CdBR) content as well as the YieldBR were highly dependent on both the soil amendment materials' pH and watering amount. Among all the watering treatments, 3/72 treatment (15% less irrigation water than the CON) with ZVIB 6.3 amendment was the optimum fit for simultaneous reduction of AsBR (50%) and CdBR contents (19%) as well as for significant increment (12%) of the YieldBR. Although high pH (9.7) ZVIB application could also efficiently decrease As and Cd contents in brown rice, it might risk grain yield lost if appropriate (e.g. 3/72 in our study) watering management technique was not chosen. Therefore, ZVIB would be an environmentally friendly option as an amendment material with proper selection of watering management technique to utilize As and Cd co-contaminated arable soils safely for paddy cultivation.


Assuntos
Oryza , Poluentes do Solo , Cádmio/análise , Carvão Vegetal , Concentração de Íons de Hidrogênio , Ferro , Rizosfera , Solo , Poluentes do Solo/análise , Água
16.
Medicine (Baltimore) ; 99(45): e23122, 2020 Nov 06.
Artigo em Inglês | MEDLINE | ID: mdl-33157990

RESUMO

INTRODUCTION: Hemorrhoidal disease is one of the most common and frequently occurring benign anorectal disorders, presented with bleeding and prolapsed, and surgery is the main and effective method for severe prolapsed hemorrhoids. Yet, the recurrence rate after procedure for prolapse and hemorrhoids (PPH) is significantly higher. To reduce the recurrence rate and protect the anus function, we try to carry out a randomized, controlled, prospective study to compare the efficacy and recurrence rate of tissue selecting technique (TST) with mega-window stapler (TST-MS) combined with anal canal epithelial preservation operation and PPH combined with external hemorrhoidectomy and inferior internal hemorrhoid ligation operation for the treatment of severe prolapsed hemorrhoids. METHODS: This study is a single-center, evaluator-blinded, randomized, controlled clinical trial. Participants meet the inclusion and exclusion criteria in this RCT will be randomly divided into treatment group (TST-MS combined with anal canal epithelial preservation operation group) and control group (PPH combined with external hemorrhoidectomy and inferior internal hemorrhoid ligation operation) in a 1:1 ratio according to a computer-generated randomization list. The outcomes of recurrence, anal function, intraoperative variables, and postoperative complications will be recorded at different follow-ups. CONCLUSION: The findings of the study will help to explore the efficacy and recurrence rate of TST-MS combined with anal canal epithelial preservation operation on the treatment of severe prolapsed hemorrhoids. TRIAL REGISTRATION: This study protocol was registered in open science framework (OSF). (Registration number: DOI 10.17605 / OSF.IO / 4JYNF).


Assuntos
Hemorroidectomia/métodos , Hemorroidas/cirurgia , Ensaios Clínicos Controlados Aleatórios como Assunto/métodos , Prolapso Retal/cirurgia , Grampeamento Cirúrgico , Método Duplo-Cego , Hemorroidas/complicações , Humanos , Mucosa Intestinal , Ligadura/métodos , Tratamentos com Preservação do Órgão , Estudos Prospectivos , Prolapso Retal/etiologia , Índice de Gravidade de Doença , Grampeamento Cirúrgico/métodos
17.
Medicine (Baltimore) ; 99(39): e22456, 2020 Sep 25.
Artigo em Inglês | MEDLINE | ID: mdl-32991483

RESUMO

BACKGROUND: Functional constipation refers to constipation without organic lesions caused by dietary factors, mood depression, changes in life rules, and poor bowel habits. Clinically, constipation is mainly manifested by changes of stool texture, difficulty or lack of bowel movement, and dry stool. Sometimes, it can be accompanied by abdominal distension and abdominal discomfort. Chinese herbal compound is a prescription which is composed of 2 or more medicinal flavors and is designed for relatively certain diseases and syndromes. Clinical studies have shown that TCM compounds have a good therapeutic effect on functional constipation, but there is no evidence of evidence-based medicine. The purpose of this study is to systematically evaluate the efficacy and safety of TCM compounds in the treatment of functional constipation, and to provide evidence-based basis for the clinical application of TCM compounds in the treatment of constipation. METHODS: A systematic search was performed on English database (PubMed, Embase, Web of Science, the Cochrane Library) and Chinese database (CNKI, Wanfang, Weipu (VIP), CBM), in addition to the manual retrieval of Baidu and Google academic for randomized controlled trials (RCTs) on the treatment of functional constipation with Chinese herbal compound. The retrieval time limit was from the establishment of the database to August 2020. Two researchers independently screened the literature, extracted the data and evaluated the quality of the included studies. A meta-analysis was performed using RevMan5.3 software. RESULTS: In this study, the efficacy and safety of TCM herbal compounds in the treatment of functional constipation were evaluated by the overall effective rate, recovery rate, colonic transmission function, and other indicators. CONCLUSIONS: This study will provide reliable evidence-based evidence for the clinical application of Chinese herbal compound in the treatment of functional constipation. OSF REGISTRATION NUMBER: DOI 10.17605/OSF.IO/D5ECF.


Assuntos
Constipação Intestinal/tratamento farmacológico , Medicamentos de Ervas Chinesas/uso terapêutico , Humanos , Metanálise como Assunto , Fitoterapia , Revisões Sistemáticas como Assunto
18.
Sci Total Environ ; 748: 141536, 2020 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-32798881

RESUMO

The dispersities of goethite nanoparticles (GTNPs) and ferrihydrite nanoparticles (FHNPs) affect the transport and retention of nanoparticle-associated contaminants. However, the effects of interaction on nanoparticle stability under varying environmental conditions have not been previously investigated. This study utilized settling experiments, a semi-empirical model, and the Derjaguin-Landau-Verwey-Overbeek (DLVO) theory to study the homo-aggregation and hetero-aggregation of GTNPs and FHNPs. The pure system of GTNPs tended to aggregate more easily than that of FHNPs, especially under the conditions of high pH (7.0-9.0), high ionic strength (IS, 10 mM), and low concentrations of humic acid (HA) (2 mg L-1). This aggregation was attributed to the elongated morphology of GTNPs, which contributed to surface heterogeneity. The GTNPs and FHNPs mixtures rapidly coagulated, particularly under the surface-charge disequilibrium caused by an increase in negative charges or IS. Hetero-aggregation increased with increase in the GTNPs ratio, indicating that the elongated GTNPs dominated the coagulation of the Fe mineral nanoparticle mixture, which was attributed to the surface heterogeneity and high probability collisions between the GTNPs. Although DLVO neglects the influence of heterogeneity on the nanoparticle surfaces, SEM revealed that hetero-aggregation of GTNPs and FHNPs occurred. The results obtained in this study provide novel and valuable insights into the behaviors of GTNPs and FHNPs mixtures and suggest that during the gradual transformation of FHNPs to GTNPs in soil or aquatic environments, the hetero-aggregation of GTNPs and FHNPs may be enhanced, thus promoting contaminant immobilization.

19.
Huan Jing Ke Xue ; 41(5): 2292-2300, 2020 May 08.
Artigo em Chinês | MEDLINE | ID: mdl-32608847

RESUMO

Agglomeration and dispersion of nanoparticles control many important environmental processes. In this study, the particle size and zeta potential of ferrihydrite nanoparticles (FHNPs) and goethite nanoparticles (GTNPs) under different pH, ion, and organic matter conditions were measured. These data were used to calculate the Derjaguin-Landau-Verwey-Overbeek (DLVO) interaction energy between nanoparticles to further investigate the stability of two nanoparticles. The results showed that Na+ and Ca2+ promoted FHNPs and GTNPs agglomeration due to their ionic strength. The PO43- with low-concentration (2 mmol·L-1), humic acid and fulvic acid (2 mg·L-1 and 10 mg·L-1) loaded on iron mineral nanoparticles changed their surface charge and further improved the stability of FHNPs and GTNPs at medium and high pH. Although the PO43- with high concentration (10 mmol·L-1) also changed the electrical properties of iron mineral nanoparticles, it had little contribution to the GTNP stability due to its ionic strength. When the zeta potentials of FHNPs or GTNPs were close to 0, the primary barrier and secondary minima were nonexistent simultaneously. The two kinds of nanoparticles irreversibly agglomerated in primary minima. When the primary barrier and secondary minima coexisted, the proportion of reversible aggregation of FHNPs and GTNPs in secondary minima increased. The results provided support for further investigation of the environmental behavior of FHNPs and GTNPs, and iron mineral nanoparticle-facilitated transport of pollutants.

20.
Environ Sci Pollut Res Int ; 27(29): 36377-36390, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32562227

RESUMO

The consumption of agricultural products grown on paddy soils contaminated with toxic element has a detrimental effect on human health. However, the processes and mechanisms of iron (Fe) mineral-associated arsenic (As) availability and As reactivity in different paddy soil profiles are not well understood. In this study, the fractions, immobilization, and release risk of As in eleven soil profiles from the Changzhutan urban agglomeration in China were investigated; these studied soils were markedly contaminated with As. Sequential extraction experiments were used to analyze fractions of As and Fe oxide minerals, and kinetic experiments were used to characterize the reactivity of Fe oxide minerals. The results showed that concentrations of total As and As fractions had a downward trend with depth, but the average proportions of As fractions only showed relatively small changes, which implied that the decrease in the total As concentrations influenced the changes in fraction concentrations along the sampling depth. Moreover, we found that easily reducible Fe (Feox1) mainly controlled the reductive dissolution of the Fe oxides, which suggest that the reductive dissolution process could potentially release As during the flooded period of rice production. In addition, a high proportion of As was specifically absorbed As (As-F2) (average 20.4%) in paddy soils, higher than that in other soils. The total organic carbon (TOC) content had a positive correlation with the amount of non-specifically bound As (As-F1) (R = 0.56), which means that TOC was one factor that affected the As extractability in the As-F1. Consequently, high inputs of organic fertilizers may elevate the release of As and accelerate the diffusion of As. Graphical abstract.


Assuntos
Arsênio/análise , Oryza , Poluentes do Solo/análise , China , Compostos Férricos , Minerais , Solo
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